The technology related to polishing semiconductor substrates has existed for many years. One problem associated with polishing is clogging of polishing pad pores by polishing particles and polishing products. Typically, a layer is polished with a slurry usually having polishing particles made of one material. For example, the polishing slurry typically includes alumina particles, silica particles, or the like, but does not include a combination of alumina and silica particles, etc.